Island



(NoMdeL) v J. D. JOHNSTON.

GALIPERS- Patent-ed Jan. 5, 1897.

UNITED STATES PATENT OFFICE.

JOHN D. JOHNSTON, OF NEWPORT, RHODE ISLAND.

CALIPERS.

SPECIFICATION forming part of Letters Patent No. 574,429, dated January 5, 1897. Application filed February 21, 1896. Serial No. 580,233. (No model.)

To all whom it may concern.-

Be it known that 1, JOHN D. J OHNsTON, a citizen of the United States, residing at Newport, in the county of Newport and State of Rhode Island, have invented certain new and useful Improvements in Calipers; and I do hereby declare the following to be a full, clear, and exact description of the invention, such as will enable others skilled in the art to which it appertains to make and use the same.

This invention relates to certain new and useful improvements in calipers; and it has for its objects, among others, to provide a simple and cheap construction whereby three calipers are combined in one, so that two Outside diameters can be calipered at the same time and with one pair of calipers, and capable of use as inside calipers as well.

By my invention a mechanic does not have to have so many pairs and the cost to him will be much less, besides by having the implements all in the one article there is less danger of loss of one or more of them.

Other objects and advantages of the invention will hereinafter appear, and the novel features thereof will be specifically defined by the appended claim.

The invention in this instance resides in the peculiar combinations and the construction, arrangement, and adaptation of parts, all as more fully hereinafter described, shown in the drawings,and then particularly pointed out in the claim.

The invention is clearly illustrated in the accompanying drawings, which, with the letters of reference marked thereon, form a part of this specification, and in which- Figure 1 is aplan view of my improved calipers. Fig. 2 is a similar view showing the parts in the position they assume when used as inside calipers.

Like letters of reference indicate like parts throughout the several views.

Referring now to the details of the drawings by letter, Adesignates the body portion of the device, which is of substantially the shape shown, having the arm B, terminating in the oppositely-extending points C, the body portion being of any suitable material and preferably open at the places shown, not only for lightness, but to give to the implement an ornamental appearance.

Near opposite ends of the body portion are the rounded or substantially circular portions a, to the center of each of which is pivoted a leg, upon any well-known or approved form of pivot, and the legs being preferably of substantially the shape and form shown. Each of the circular portions is formed with a curved slot F, in which is designed to travel the bolt G, held in the arm orleg, one for each, and upon the opposite side of the body portion from the leg is a washer I, and upon the bolt outside the said washer is a thumb-nut J.

In practice, the legs being in the position in which they are shown in Fig. 1, the implement is adapted for outside measurements, and it will be observed that there are two complete calipers, each formed by one leg and one of the points 0, and as each leg is adjustable independently of the other it will be seen that the two calipers may be used independently of each other, so that two outside measurements maybe taken at the same time. WVhen it is desired to set the calipers for inside measurement, all that it is necessary to do is to loosen the thumb-nuts and turn the legs on their pivots until they assume the position shown in Fig. 2 and secure the legs in any desired position by the thumb-nuts.

Modifications in detail may be resorted to without departing from the spirit of the invention or sacrificing any of its advantages.

What is claimed as new is The combination with the body portion having curved slots and oppositely-extending circular portions and the centrally-disposed fixed arm terminating in oppositely-disposed points, of the legs pivotally mounted near opposite ends of the body portion and provided with bolts working in said slots, and thumbnuts on the ends of said bolts, all substantially as and for the purpose specified.

In testimony whereof I have signed this specification in the presence of two subscribing witnesses. I

- JOHN D. JOHNSTON. IVitnesses:

DARIUS BAKER, W. O. MILNE. 

